Field of the Invention
The present invention relates to a switch-extender and a method for calibrating a measurement system with such a switch-extender, especially for testing mobile communication systems, for example mobile phones, handhelds, tablet PCs and WLAN-routers.
Discussion of the Background
Due to the increasing number of mobile communication systems, for example mobile phones, there is a strong demand in reducing the overall test time. As the complexity of mobile communication systems increases from generation to generation, the required test time also increases. Therefore, it is very difficult to reduce the test time for each mobile communication system. Therefore, the approach of the present invention is that the overall test time can be reduced significantly by testing several mobile communication systems, like mobile phones, in parallel.
Document US 2005/0264373 A1 describes a switching matrix that allows connecting multiple input ports to multiple output ports as well as to power sources. It is disadvantageous that document US 2005/0264373 A1 does not allow compensating different signal behavior in different signal path. Therefore, an input signal which is output at several ports has a different signal level which makes a switching matrix unsuitable for supplying a plurality of mobile communication systems in parallel with a test signal.